MICROORAGNISMS WITHIN AND AROUND SOIL IN CASSAVA MILL EFFLUENT

ABSTRACT

Wastewater from numerous cassava processing industries contains cyanide which is toxic to several forms of life. This effluent constitutes serious hazards to the environment and aquatic life in receiving water bodies. The identification and characterization of microorganisms isolated from cassava mill effluent contaminated soil was undertaken using standard microbiological methods. Soil samples were collected from points in a site polluted with cassava effluent and from adjacent points not impacted with the effluent pollution. The isolation and enumeration of microbial population was carried out using pour plate technique. Microbial (bacterial) identification was based on their cultural characteristics, Gram staining and biochemical tests. The total heterotrophic bacterial counts in the contaminated soil ranged from 1.0 x10⁸ - 4.6 x 10⁸ cfu/ml while the total heterophic fungal counts in the contaminated soil ranged from 2.6 x 10⁸ – 8.3 x 10⁸ cfu/ml. An increase in total aerobic bacterial count as distance increased away from the dump site was observed. A total of five bacterial genera were identified, which included Micrococcus sp., Pseudomonas sp., Bacillus sp., Klebsiella sp. and Escherichia coli. The fungal isolates identified include Aspergillus sp., Penicillum sp., Mucor sp., Rhizopus sp. and Saccharomyces sp. The result of the starch hydrolysis of the most abundant microorganism; Bacillus sp. showed that amylase is the enzyme responsible for the breakdown of the starch content present in the contaminated site hence making the organism able to strife better in the effluent site.